The contractor provides computer-related research and support services for the scientific studies of the Radiation Epidemiology Branch (REB). This includes research and development in computer science to develop specialized software, the use of existing software and systems to support REB projects, and the development of custom programs and systems. Computer programs are written primarily in high level languages compatible with the NIH computing system, e.g., PL1, FORTRAN, and C. Extensive support is also required for software development of sophisticated epidemiologic analysis programs for use on personal computers. Existing generalized software packages, such as SAS, are used extensively for statistical computation, retrieval, and report generation. The contractor provides data tech services such as coding, transcribing, and on-line and off-line data entry (keying). Support is provided for approximately 15 studies per month, and involves: data base management of extremely large files; editing and updating of data files; creating data analysis files; executing and modifying analytic programs; writing custom-designed programs to conduct analysis directed by REB staff; maintaining detailed file specifications and appropriate documentation of programs and systems; and taking appropriate measures to ensure data quality and security.